Induction heating coil support

ABSTRACT

An induction heating coil support is disclosed which includes overhead support rails and tie rods interconnecting the support rails and an upper portion of the coil in a manner whereby the latter portion of the coil is supported in suspension with the axis of the coil horizontal. The coil includes axially spaced apart convolutions and the tie rods extend downwardly between adjacent convolutions and are interconnected with guide rail means disposed within the coil so as to engage the inner surface of the upper portion of the coil. The overhead support rails may extend longitudinally or transversely with respect to the coil axis, and the support rails are supported above the coil by vertical support posts at opposite ends thereof. The bottom portion of the coil rests on underlying support means provided therefore.

Unite States Patent [1 1 Kasper [54] INDUCTION HEATING COIL SUPPORT [75] Inventor: Robert J. Kasper, Seven Hills, Ohio [73] Assignee: Park-Ohio Industries, Inc., Cleveland, Ohio [22] Filed: Feb. 2, 1972 [211 App]. No.: 222,827

[52] US. Cl ..219/10.79, 219/1067 [51] lint. Cl. ..H05b 5/18 [58] Field of Search ..219/10.79, 10.67, 219/10.71,10.73,10.69

[56] References Cited UNITED STATES PATENTS 2,900,479 8/1959 Redmond et al. ..2l9/10.69 X

1,873,808 8/1932 Bailey ..219/10.79 X

2,448,010 8/1948 Baker et a1. ..2l9/l0.79 X

3,424,886 1/1969 Ross ..219/l0.67

2,052,010 8/1936 Bailey ..2l9/l0.69

2,809,263 10/1957 Segsworth ..219/l0.79 X

Primary Examiner-J. V. Truhe Assistant Examiner-B. A. Reynolds Attorney-James H. Tilberry, Alfred C. Body and Robert V. Vickers [5 7] ABSTRACT An induction heating coil support is disclosed which includes overhead support rails and tie rods interconnecting the support rails and an upper portion of the coil in a manner whereby the latter portion of the coil is supported in suspension with the axis of the coil horizontal. The coil includes axially spaced apart convolutions and the tie rods extend downwardly between adjacent convolutions and are interconnected with guide rail means disposed within the coil so as to engage the inner surface of the upper portion of the coil. The overhead support rails may extend longitudinally 0r transversely with respect to the coil axis, and the support rails are supported above the coil by vertical support posts at opposite ends thereof. The bottom portion of the coil rests on underlying support means provided therefore.

16 Claims, 7 Drawing Figures INDUCTION HEATING COIL SUPPORT This invention relates to the art of induction heating and, more particularly, to arrangements for supporting an induction heating coil.

Induction heating coils have been provided heretofore for the purpose of statically or progressively heating a large metal slab or workpiece or for simultaneously and progressively heating a plurality of metal workpieces such as rods which are positioned in side by side relationship during movement thereof through the coil. Such a slab or the plurality of rod-like workpieces may have a length dimension exceeding 20 feet. It is most desirable to heat such a slab or plurality of workpieces with the longest dimension thereof, when the slab is in the coil, extending parallel to the coil convolutions and with the next longest dimension thereof, the width dimension, extending parallel to the coil axis. Accordingly, the coil configuration required to achieve the desired heating is of a generally rectangular configuration when viewed in the direction of the axis of the coil and includes a pair of opposed parallel long convolution portions interconnected at the corresponding ends thereof by relatively short convolution portions. To facilitate introducing or removing a slab from the coil or progressively feeding a plurality of rod-like workpieces therethrough, it is preferred that the coil be disposed with the opposed long convolution portions thereof in parallel horizontal planes.

An induction heating coil of the above character is constructed from tubular conductive material such as copper and includes a pair of coil ends adapted to be connected across an alternating current power source for energization of the coil. The tubular construction provides for the opposite ends of the coil to be connected to a source of cooling fluid which is circulated through the coil to prevent overheating thereof. Further, the convolutions of the coil are embedded in refractory insulating material, and other insulating materials are often provided within the coil opening to reduce heat losses from the workpiece during an induction heating operation. It will be appreciated, therefore, that the coil is not only physically large but also is extremely heavy. Accordingly, it becomes necessary to support the upper and lower portions of the coil in a manner whereby the weight of the materials of these portions do not distort the coil configuration. The bottom portion of the coil can be readily supported by a suitable underlying support structure upon which the coil rests. Support of the upper coil portion, however, is not so easily achieved. Moreover, if the upper portion is not adequately supported it will sag between the side portions of the coil, whereby the coil configuration is distorted. More importantly, such sagging of the upper portion of the coil subjects the tubular conductor material, refractory insulating material and any other insulating material associated with the coil to stresses which can damage the coil unit and adversely effect its operation. Moreover, excess sagging can distort the inner contour of the coil to the extent that clearances between the workpiece and inner surfaces of the coil are undesirably reduced.

Coil supporting arrangements heretofore provided do not adequately fill the need for support means which can be associated with a coil of the above character in a manner whereby the desired support function is achieved economically and with a minimum number of support components associated with the coil, and in a manner whereby relative adjustment of the support means and coil and the assembly and disassembly of the coil with respect to the support means is readily facilitated. More particularly, certain prior art arrangements require direct connection between the coil convolutions and support means therefor. Such a connection is achieved, for example, by a plurality of fastener components rigidly attached to the coil convolutions and interengagable with support beams disposed in overlying engagement with the coil. Such an arrangement not only involves the time and expense of mounting the fasteners on the coil, but requires precise alignment between the fasteners and cooperating fastening means associated with the beams. Accordingly, such an arrangement is expensive to construct. Further, the support beams are constructed of insulating material for economic purposes and, therefore, must be quite large in cross section in order to provide the mechanical or structural stability required by the ;coil size. Thus, the coil is substantially surrounded by a-bulky mass of support components making access to outer areas of the coil quite difficult. Still further, the large support beams are cumbersome to manipulate during assembly of the coil with the support structure, thus further increasing the difficulty and expense of the assembly operation.

In accordance with the present invention, a coil support arrangement is provided by which the foregoing disadvantages and others of arrangements heretofore known are avoided. In this respect, an induction heating coil of the foregoing character is supported by means including overhead supports spaced above the coil and interconnecting components which extend between the overhead supports and the coil. More particularly, the interconnecting components extend between adjacent convolutions of the upper portion of the coil and engage the inner surface of the upper portion of the coil, whereby the latter is supported in suspension. By suspending the upper coil portion in the foregoing manner less accuracy is required with respect to aligning the interconnecting components with the coil and overhead supports during assembly thereof, whereby a considerable reduction in assembly time and cost is advantageously realized. The interconnecting components between the coil and overhead supports may be defined in part by tie rod elements depending from the overhead supports and projecting through the space between adjacent coil convolutions. With the use of rod elements to achieve the suspension function, a minimum of the outer area of the coil is obstructed, whereby the outer area of the coil is readily accessible for maintenance, and is available for support of equipment such as capacitor units. Moreover, the opposite ends of the tie rods can be adjustably interengaged with the overhead support and coil to provide for readily adjusting the interconnection therebetween to achieve the most desirable support posture for the coil.

In accordance with another aspect of the present invention, the overhead supports include rail elements readily adapted to be arranged to support coils having various transverse and longitudinal dimensions in a manner whereby a minimum number of support components are required for a given coil size. In this respect, the overhead support rails can be arranged to extend either longitudinally of or transverse to the coil axis. The arrangement of the rails depends on the dimensions of the coil and the particular disposition of the support rails which will provide for the desired support function to be achieved with a minimum amount of support rail material and other components of the support assembly.

An outstanding object of the present invention is the provision of an induction heating coil support arrangement which is more economical in construction and installation then support arrangements heretofore known.

Another object is the provision of a support arrangement for an induction heating coil wherein at least an upper portion of the coil is supported in suspension from an overhead support structure.

Yet another object is the provision of an induction heating coil support arrangement of the foregoing character wherein suspension of the upper coil portion is achieved without direct engagement between the heating coil and overhead support structure.

A further object is the provision of an induction heating coil arrangement of the above character wherein suspension of the upper coil portion is achieved in a manner whereby maximum accessibility to the coil and maximum usable space is obtained.

Yet another object is the provision of a support arrangement of the foregoing character which is readily adaptable to the support of induction heating coil units having different lateral and longitudinal dimensions.

Still another object of the present invention is the provision of a coil support arrangement of the above character wherein adjustment of the support components is provided for and can be readily achieved.

The foregoing objects and others will in part be obvious and in part more fully pointed out hereinafter in conjunction with the description of the drawing of preferred embodiments of the invention and in which:

FIG. 1 is a schematic illustration of one form of an induction heating coil adapted to be supported in accordance with principles of the present invention;

FIG. 2 is an end elevation, partially in section, of a support arrangement for a coil unit including a coil having a configuration similar to the coil in FIG. 1;

FIG. 3 is a side elevation view, partially in section, of the arrangement illustrated in FIG. 2, the section being along line 3--3 in FIG. 2;

FIG. 4 is a sectional elevation of a portion of the support arrangement illustrated in FIG. 2, the section being along line 44 in FIG. 2;

FIG. 5 is a sectional elevation of a portion of the arrangement illustrated in FIGS. 2 and 3, the section being along line 55 in FIG. 3;

FIG. 6 is a side elevation, partially in section, of another embodiment of an induction heating coil support arrangement in accordance with the present invention; and

FIG. 7 is an end elevation, partially in section, of the arrangement illustrated in FIG. 6.

Referring now to the drawing in greater detail wherein the showings are for the purpose of illustrating preferred embodiments of the invention only and not for the purpose of limiting the same, an induction heating coil 10 is schematically illustrated in FIG. 1. Coil 10, in a manner well known, is defined by a plurality of convolutions 12 of tubular conductive material such as copper and has opposite ends 14 and 16 adapted to be connected across a suitable source of alternating current for energizing the coil. Further, ends 14 and 16 define inlet and outlet means for circulation of a suitable cooling fluid through the coil.

Coil 10 has an axis A and is adapted to axially receive a workpiece W to be heated, which workpiece may be defined by a metal slab or a plurality of metal bars disposed side by side with their axes extending laterally of coil axis 10. workpiece W is illustrated as being associated with coil 10 in a manner whereby the longest or length dimension L of the workpiece extends parallel to convolutions 12, its next longest or width dimension B extends parallel to coil axis A, and its narrowest or heighth dimension H extends perpendicular to the plane of convolutions 12. It has been found that this relationship between a workpiece and coil provides for the most efficient heating of the workpiece. The workpiece can, of course, be heated statically within the coil or can be advanced through the coil and progressively heated thereby. It will be appreciated that the coil convolutions 12 define a coil configuration which includes long upper and lower coil portions 18 and 20, respectively, which are parallel to one another and are interconnected along corresponding sides by short side portions 22. Whether heating of workpiece W is achieved statically or progressively, it will be appreciated that the workpiece must be supported relative to the coil during heating of the workpiece and that the coil portions must be suitably supported. More particularly, the long upper and lower portions 18 and 20 of the coil must be supported in a manner whereby the tubular conductor material and insulating material associated therewith is not adversely effected by stresses imposed thereon as a result of the weight of the materials and the length of the coil portions between sides 22.

In accordance with the present invention, support of an induction heating coil of the foregoing character can advantageously be achieved in the manner illustrated in FIGS. 2, 3, 4 and 5 of the drawing. In this respect, a coil unit 24 is illustrated which includes an induction heating coil 26 similar to coil 10 discussed above. In this respect, coil 26 is defined by a continuous tube of conducting material such as copper which is wound to define a coil configuration which is substantially rectangular when viewed along the axis of the coil and which is provided with opposite ends 28 and 30 adapted to be connected across a suitable source of alternating current, not illustrated. Further, ends 28 and 30 are adapted to be connected to a source of cooling fluid in a manner whereby end 28, for example, defines inlet means and end 30 outlet means for circulation of the cooling fluid. Further, coil 26 has an upper portion 32 and a lower portion 34 and side portions 36. Upper portion 32, lower portion 34, and side portions 36 are each defined by a plurality of axially spaced apart coil convolutions 38. While the conductor defining coil 26 is illustrated as being circular in cross section, it will be appreciated that the conductor may have any desired cross sectional configuration such as square or rectangular, for example.

Coil 24 includes inner and outer surfaces which are defined by suitable insulating material disposed on radially opposite sides of coil 26. In the embodiment illustrated, the inner surface of the coil unit is defined by refractory brick elements 40 disposed within the coil adjacent upper and lower portions 32 and 34 and side portions 36 thereof. Moreover, in the embodiment illustrated, the outer surface for the coil is defined by cast refractory material 42 disposed radially outwardly of refractory brick elements 40 and in which coil convolutions 38 are embedded. The refractory insulation as defined by bricks 40 and cast refractory 42, of course, serves to retain heat within the coil during an induction heating process and to reduce undesired transmission of heat to the work area surrounding the coil units. Moreover, bricks 40 provide an air gap between coil 26 and a workpiece W disposed in the coil unit. Accordingly, it will be appreciated that insulating arrangements other than the specific arrangement illustrated may readily be employed for this purpose and to define the inner and outer surfaces of the coil.

It will be appreciated that the coil unit defined by coil 26 and insulatingmaterial 40 and 42 is quite heavy and that the support of upper and lower portions 32 and 34 of the coil unit must be achieved in a manner whereby the structural integrity of the coil unit is maintained. Such support is achieved in accordance with the present invention by providing underlying support means 44 upon which lower portion 34 of the coil unit rests and overhead support means 46 providing for support of upper coil portion 42 in suspension. More particularly, underlying support means 44 may be defined in any suitable manner and could, for example, be defined by an underlying support surface such as a floor. Preferably, however, the underlying support is defined by a relatively thick slab of refractory insulating material 48 upon which lower coil portion 34 rests and a support base 50 which suitably supports slab 48 in an elevated disposition. Base 50 may be defined by any suitable material and, preferably, is of a cast material such as concrete. A plurality of non-magnetic metal guide rails 52 extend longitudinally through the coil either in engagement with or in close proximity to the lower inner surface of the coil unit as defined by brick elements 40. Guide rails 52 are adapted to receive and support a workpiece W during its movement into and out of the coil unit and during static disposition of the workpiece in the coil unit so as to protect the inner surfaceof the coil unit from direct engagement with the workpiece. Lower guide rails 52 may be suitably supported vertically such as by metal support rods 54 having upper ends attached to the guide rails such as by welding and lower ends suitably interconnected with support base 50 in a manner to assure that the guide rails are rigidly maintained in their vertical dispositions so that the weight of a workpiece thereon does not cause the guide rails to damagingly engage the inner surface of the coil unit. For example, the lower ends of rods 54 may be rigidly and insulatedly coupled with metal plates 56 embedded in the material of base 50. It will be appreciated, however, that the lower guide rails may be supported in a manner whereby the elevation thereof relative to the inner surface of the lower coil portion is adjustable. Rods 54 advantageously extend downwardly from guide rail 52 through suitable openings between bricks elements 40, through coil insulating material 42 and between adjacent coil convolutions 38, whereby any movement which might be imparted to rods 54 and lower guide rails 52 during movement or static support of a workpiece relative to the coil unit advantageously does not physically effect the coil unit. Further, it will be appreciated that the foregoing structure provides for the lower support rails to be readily associated with a given coil unit since no mechanical interconnection therebetween is required and only the openings for the rods have to be provided in the insulating material of the coil unit.

Overhead support structure 46 includes support rail means which, in the present embodiment, is defined by a pair of support rails 58 extending horizontally and transversely across coil unit 24 at spaced apart locations along the length thereof. Support rails 58 may be of any suitable construction and, preferably, are steel channel beams vertically supported in the overhead position by metal support posts 60 and cross beams 61 at opposite ends thereof. It will be appreciated that rails 58 could be directly supported by posts 60 at opposite ends, the use of cross beams 61 merely being a preferred arrangement. Support rails 58 and the corresponding cross beams 61, and beams 61 and posts 60 may be interconnected in any suitable manner, such as by welding. Moreover, it will be appreciated that support rails 58 may be supported in the overhead position thereof by means other than ground engaging support posts. The overhead support structure further includes means interconnecting support rails 58 and upper coil portion 32. More particularly, in the preferred embodiment the interconnecting means includes metal rod elements 62 and guide rail components 66. Rods 62 depend from support rails 58 and extend through suitable openings in refractory material 42 and between adjacent refractory brick elements 40 defining the inner surface for upper coil portion 32. Preferably, the upper ends of rods 62 are threaded to receive insulated nuts 64. The threads on the upper ends of rods 62 extend axially thereof for a distance which provides for the axial position of the rod relative to the corresponding support rail to be readily adjusted by adjusting the position of the corresponding nut 64 therealong.

A plurality of upper guide rails 66 extend longitudinally of the coil axis and engage the inner surface of refractory brick elements 40 of upper coil portion 32. Upper guide rails 66 are provided with studs 68 having lower ends suitably interconnected with the guide rails such as by welding. The upper ends of studs 68 are provided with internally threaded recesses 70, and the lower ends of rods 62 are externally threaded for cooperative engagement with recesses 70. Preferably, threads on the lower ends of rod 62 and the axial depth of threaded recesses 70 are such as to provide for rods 62 to be axially adjustable relative to upper guide rails 66. Thus, by altering the axial position of a rod 62 relative to a guide rail 66 or to a support rail 58 to distance between the guide rail and support rail can be varied, whereby support of the coil unit by the overhead support means is readily and advantageously adjustable. Such adjustment facilitates assuring proper supporting engagement between the upper support rails and upper coil portion 32 at the various supporting points laterally and longitudinally of the coil portion. It is to be noted too that rod elements 62 extend through suitable openings in upper coil portion 32 and between adjacent coil convolutions 38, whereby there is no direct mechanical connection between the coil unit and overhead support means. Thus, relative movement between upper coil portion 32 and the overhead support means such as might result from expansion and construction of the coil unit is accommodated without damaging the coil unit.

In the present embodiment, a pair of support rails 58 extend laterally of coil unit 24 and three rod elements 62 depend from each support rail for interconnection within the coil unit with the corresponding one of three upper guide rails. The guide rails define means engaging the inner surface of upper coil portion 32, and it will be appreciated that such surface engaging means could readily be defined by other structures and could, for example, be defined by square, rectangular or other plate configurations as opposed to the elongated guide rail elements illustrated. Moreover, it will be appreciated that the number of depending rods employed may vary and that more than two support rails could be employed if desired, and that the number of support rails and depending rods employed for a given coil unit will depend in part on the coil unit dimensions and the extent to which support is found necessary or desirable for the coil. Still further, it will be noted that the term rod is intended to include any elongate component capable of interconnection with the support rails and inner surface engaging means and, in this respect, could for example be deinfed by any solid or tubular component having any desired cross sectional configuration or by stranded cable means. It should be noted too that adjustability of such rods while preferred is not absolutely necessary and that adjustment can be provided for in any suitable manner.

In accordance with another aspect of the present invention, refractory bricks 40 are provided in longitudinal sections having lateral edges 41 which overlie the opposite side portions of each upper and lower guide rail element. This relationship is illustrated in detail in FIG. with respect to bricks 40 associated with upper guide rails 66. Thus, for each guide rail 66 a longitudinally extending space is defined between adjacent faces of sides 41 of the brick elements supported thereby. This longitudinal space advantageously provides for the studs 68 spaced along the length of rail 66 to be provided with longitudinally extending openings 72 through which cooling conduits or tubing 74 extend from one end of the guide rail to the other. The opposite ends of conduits 74 are adapted to be connected to a suitable source of cooling fluid, not illustrated, to facilitate the circulation of cooling fluid along the radially outward surface of the guide rails. This advantageously provides for maintaining the guide rails cool during an induction heating operation. It will be appreciated, of course, that lower support rails 52 are similarly cooled.

In accordance with yet another aspect of the present invention, means may be provided between refractory brick elements 40 and the corresponding upper and lower coil portion for maintaining coil convolutions 38 in the desired space relationship with respect to one another, with respect to refractory brick elements 40 and with respect to the corresponding rod elements 54 and 62. Suitable spacing means for this purpose is illustrated in FIGS. 4 and 5 of the drawing in conjunction with outer coil portion 32. In this respect, a pair of spacer components 76 and 78 of suitable non-magnetic material are disposed on opposite sides of rod elements 62 and extend longitudinally of the coil axis and, ac cordingly transverse to the axes of convolutions 38. The inner surfaces of components 76 and 78 are pro vided with opposed pairs of arcuate recesses 80 and 82 respectively, which are adapted to receive a convolution 38 therebetween. It will be appreciated therefore that coil convolutions 38 are maintained in the desired space relationship with respect to one another and with respect to rods 62 and insulating bricks 40. It will be further appreciated that similar spacing means may be provided for lower coil portion 34 if desired. In the embodiment illustrated, theouter ends of spacers 76 between rods 62 are interconnected by side elements 76a and spacers 78 are interconnected by side portions 78a and bottom portion 78b. This advantageously provides for maintaining the spacers adjacent rods 62 and, further, facilitates filling the space between the spacers with cast refractory material 42. While it is preferred to provide spacer components of this structure and in pairs on opposite sides of rods 62, it will be appreciated that other arrangements can readily be employed. For example, the spacers could be defined by pre-cast insulating slabs having recesses to receive the convolutions. Pairs of support components of the above character are preferred, however, in that this structure provides for assembly and adjustment of the support arrangement to establish the desired convolution spacing, rod spacing and coil support before the coil convolutions are embedded in refractory insulating material 42, whereby possible damage to the latter material as a result of manipulation of the coil or support means is advantageously avoided. It will be appreciated too that the number and positions of such spacers can readily be varied.

In accordance with another aspect of the present invention, yoke means in the form of a plurality of iron laminations 84 may be positioned on the upper surface of refractory insulating material 42 of upper coil portion 32 to shield the support rails and vertical support posts from stray fields which might otherwise cause these components to be undesirably heated during an induction heating process. The provision of the coil assembly with such yoke means is facilitated in that the support rods 62 occupy a minimum of the exposed upper area of upper coil portion 32. Similar yoke means may be provided for the same purpose between refractory slab 48 and base 50 if the latter includes or is of metal construction. Preferably, as best seen in FIGS. 4 and 5, sleeves 63 of thermal insulating material surround the portions of rods 62 passing through the yoke to reduce heat transfer to the rods, and sleeves of insulating material surround the upper ends of rods 62 to reduce heat transfer from the rods to beams 58.

In FIGS. 2-4 of the drawing, a bank of capacitors defined as a unit 85 is illustrated by broken lines as being disposed on support rails 58. A laminate 87 of suitable insulating material is disposed between the support rails and unit 85. Preferably, unit 85 includes a housing or enclosure of insulating material from which busses (not illustrated) lead to opposite ends of the coil. Unit 85 can be interconnected with rails 58 in any suitable manner to secure the unit against movement relative to the rails such as might occur as a result of vibration during an induction heating process. Mounting of devices such as the capacitor unit above the coil advantageously reduces floor space requirements, removes the unit from the path of falling scale which can short circuit the capacitors, and minimizes transmission losses by permitting the use of short connecting busses to the coil.

In the foregoing embodiment, overhead support rails 58 extend laterally of the coil unit and a pair of the support rails are disposed in axially spaced apart relationship relative to the coil axis. While a support arrangement of this character is capable of supporting coil units having various lateral widths, it will be appreciated that the longest dimension of certain workpieces to be inductively heated will be such that the lateral width of the coil unit will be so large as to make it impractical to employ support rails extending laterally thereacross. Such rails would necessarily be extremely long and accordingly difficult to handle and manipulate during construction of the support arrangement. Moreover, as the length of the rails increases the cross sectional dimensions thereof must be increased to prevent sagging of the beam as a result of coil unit weight. In accordance with the present invention, however, the support rail arrangement can be readily modified to accommodate coil units having too large a lateral width for the support arrangement described hereinabove. In this respect, with reference to the embodiment illustrated in FIGS. 6 and 7 of the drawing, the support rail means can be positioned to extend longitudinally of the coil axis. More particularly, a plurality of overhead support rails 90 which may be similar to support rails 58 can be laterally spaced apart relative to the axis of a coil unit 92 which preferably is similar to coil unit 24 in all respects other than the dimensions thereof. Accordingly, a detailed description of coil unit 92 is not necessary. The support arrangement, in the manner described hereinabove, includes underlying support means 94 and overhead support means including support rails 90 and depending support rods 96. The upper and lower ends of rods 96 are interconnected with support rails 90 and upper guide rails 98 within coil unit 92 in the manner described hereinabove with regard to support rails 58 and guide rails 66. In this embodiment, however, guide rails 98 are parallel and disposed beneath a corresponding one of the support rails 90, whereby each guide rail 98 is adjustably supported relative to a corresponding one of the support rails 90. Support rails 90 may be vertically supported in any suitable manner such as by vertical support posts 100 and cross beams 101 at opposite ends thereof. Moreover, support rails 90 extend beyond the longitudinal opposite ends of coil unit 92 a distance sufficient to provide space between support posts 100 and a corresponding end of coil unit 92 for equipment 102 and 104 defining support means to facilitate introduction and removal of workpieces W from the coil unit, as described more fully hereinafter. It will be appreciated that in accordance with this embodiment a support arrangement may be provided for a coil unit having a given lateral dimension, which support arrangement requires a minimum amount of space and employs structural components which advantageously can be of a length and cross sectional dimension which more readily facilitates the handling thereof during construction while providing the required structural integrity for the support arrangement. At the same time, all of the desired coil support features of the embodiment of FIGS. 2-5 are retained. In this respect, the support rods extend downwardly between adjacent coil convolutions and support the upper coil portion in suspension and in a manner whereby relative movement between the coil portion and overhead support means is facilitated without physical damage to the coil portion. Further, the support components are adjustable to facilitate achieving the best interengagement between the coil portion and support components. Still further, cooling of the upper and lower guide rail elements is facilitated as is the employment of yoke means to prevent heating of the overhead support rail and vertical support components of the support structure.

As in the previous embodiment, yoke means 106 is provided on top the coil unit to protect the metal support components from stray fields, and similar yoke means may be provided beneath the coil unit if desired. Further, insulating sleeves 108 surround rods 96 in the area of yoke means 106 and insulating sleeves 110 surround the upper ends of rods 96 at their points of connection with beams 90. As described hereinabove with regard to the first embodiment, the support rails 90 of the overhead support structure advantageously facilitate the mounting of devices such as a capacitor unit 112 above the coil unit.

A further feature of the present invention is illustrated in FIG. 6. In this respect, workpiece handling equipment 104 on the output side of the apparatus includes a suitable workpiece receiving and transferring conveyor 114, and a workpiece holdback assembly comprised of a reciprocable workpiece engaging and guiding member 116 and a hydraulic or pneumatic cylinder 118 for moving member 116. A plurality of bar workpieces W are adapted to be disposed in the coil unit and indexed therethrough during a heating operation. The introduction of a workpiece into the input end of the coil and indexing of the workpieces to achieve discharge of a heated workpiece can be achieved in any suitable manner. Workpiece engaging and guiding member 116 is operable to assure proper alignment of the workpieces relative to the coil and to guide the discharge of a heated workpiece. More particularly, member 116 is advanced by cylinder 118 into engagement with an endmost workpiece W at the discharge end of the coil. As the workpieces are indexed toward the discharge end, member 116 is moved toward cylinder 118 and against the hydraulic or pneumatic force of the cylinder, whereby the workpieces are maintained longitudinally aligned as workpiece W is discharged. When workpiece W has advanced sufficiently outwardly from the discharge end of the coil it slides down onto conveyor 114 and is transferred away from the coil. A door 120 of suitable insulating material may be provided to close the discharge end of the coil during heating of the workpieces between indexing operations. Following the succeeding heating period, door 120 is pivoted or otherwise moved to open the discharge end of the coil, cylinder 118 is actuated to advance member 116 into engagement with the endmost workpiece, and the workpieces are again indexed to achieve discharge of the endmost workpiece as described above.

It will be appreciated, of course, that discharge control and workpiece guiding of the foregoing character can be employed with either embodiment of the support arrangement described herein as well as with other coil units through which workpieces are progressively indexed and heated. Moreover, it will be appreciated that a workpiece engaging and guiding assembly of this character can be employed in conjunction with the heating and discharge of a single workpiece as opposed to a plurality of bar workpieces of the character illustrated in FIGS. 6 and 7.

As many possible embodiments of the present invention may be made and as many possible changes may be made in the embodiment herein illustrated and described, it is to be distinctly understood that the forego ing descriptive matter is to be interpreted merely as illustrative of the present invention and not as a limitation.

I claim:

1. A support for an induction heating coil unit including an induction heating coil having axially spaced convolutions enclosed by insulating means having an inner surface spaced radially inwardly of said convolutions, said support including underlying support means on which a portion of said coil unit is disposed and overhead support means for vertically supporting another portion of said coil unit in suspension, said overhead support means including support rails, means supporting said support rails in overlying relationship with respect to said other coil unit portion, and interconnecting means between said support rails and said other coil unit portion including metal guide rails extending longitudinally of the coil axis and engaging the inner surface of the insulating means of said other coil unit portion, and rod means extending through said insulating means and between coil convolutions and having opposite ends connected one to said support rails and the other to said guide rails.

2. The support according to claim 1, wherein said support rails are axially spaced apart with respect to said coil, and said rod means includes a plurality of rods associated with each support rail and having upper ends interconnected with the corresponding support rail and lower ends interconnected each with a different one of said guide rails.

3. The support according to claim 2, wherein the interconnection of at least one of the ends of at least one of said rods with the corresponding support rail and guide rail is adjustable to vary the distance between the corresponding support rail and guide rail.

4. The support according to claim 2, wherein said coil has input and discharge ends, and means outwardly adjacent said discharge end and operable to engage a workpiece in said coil to guide movement of said workpiece in the direction from said input toward said discharge end.

5. The support according to claim 1, wherein said support rails are transversely spaced apart with respect to the coil axis and each of said guide rails is disposed vertically beneath one of said support rails, and wherein said rod means includes a plurality of rods associated with each of said support rails and having upper ends interconnected with the corresponding support rail and lower ends interconnected with the guide rail therebeneath.

6. The support according to claim 5, wherein the interconnection of at least one of the ends of at least one of said rods with the corresponding support rail and the guide rail therebeneath is adjustable to vary the distance between the support rail and guide rail.

7. The support according to claim 1, wherein said coil has input and discharge ends, and means outwardly adjacent said discharge end and operable to engage a workpiece in said coil to guide movement of said workpiece in the direction from said input toward said discharge end.

8. A support for an induction heating coil unit including an induction heating coil having axially spaced convolutions and an inner surface, said support including underlying support means on which a portion of said coil is disposed and overhead support means for vertically supporting another portion of said coil in suspension, said overhead support means including support rails, means supporting said support rails in overlying relationship with respect to said other coil portion, interconnecting means between said support rails and said other coil portion including means extending between the coil convolutions of said other coil portion and guide rails extending longitudinally of the coil axis and engaging the inner surface of said other coil portion, and cooling fluid conduit means extending longitudinally of said rails.

9. A support for an induction heating coil unit including an induction heating coil having axially spaced convolutions and an inner surface, said support including underlying support means on which a portion of said coil is disposed and overhead support means for vertically supporting another portion of said coil in suspension, said overhead support means including support rails, means supporting said support rails in overlying relationship with respect to said other coil portion, interconnecting means between said support rails and said other coil portion including means extending between the coil convolutions of said other coil portion and guide rails extending longitudinally of the coil axis and engaging the inner surface of said other coil portion, said support rails extending generally transverse to the coil axis.

10. A support for an induction heating coil unit including an induction heating coil having axially spaced convolutions and an inner surface, said support including underlying support means on which a portion of said coil is disposed and overhead support means for vertically supporting another portion of said coil in suspension, said overhead support means including support rails, means supporting said support rails in overlying relationship with respect to said other coil portion, and interconnecting means between said support rails and said other coil portion including means extending between the coil convolutions of said other coil portion and guide rails extending longitudinally of the coil axis and engaging the inner surface of said other coil portion, said support rails being axially spaced apart with respect to said coil, said interconnecting means including a plurality of rods associated with each support rail and having upper ends interconnected with the cone sponding support rail and lower ends interconnected with a different one of said guide rails, said interconnection of at least one of the ends of at least one of said rods with the corresponding support rail and guide rail being adjustable to vary the distance between the corresponding support rail and guide rail, and'cooling fluid conduit means extending along each of said guide rails.

11. The support according to claim 10, and means extending between an axially spaced pair of said rods for maintaining the axial spacing of the convolutions of said other coil portion.

12. A support for an induction heating coil unit including an induction heating coil having axially spaced convolutions and an inner surface, said support including underlying support means on which a portion of said coil is disposed and overhead support means for vertically supporting another portion of said coil in suspension, said overhead support means including support rails, means supporting said support rails in overlying relationship with respect to said other coil portion, and interconnecting means between said support rails and said other coil portion including means extending between the coil convolutions of said other coil portion and guide rails extending longitudinally of the coil axis and engaging the inner surface of said other coil portion, said support rails extending generally parallel to the coil axis and being transversely spaced apart with respect to the coil axis, each of said guide rails being disposed vertically beneath one of said support rails, said interconnecting means including a plurality of rods associated with each of said support rails and having upper ends interconnected with the corresponding rails and lower ends interconnected with the guide rail therebeneath, the interconnection of at least one of the ends of at least one of said rods with the corresponding support rail and the guide rail therebeneath being adjustable to vary the distance between the support rail and guide rail, and cooling fluid conduit means extending along each of said guide rails.

13. The support according to claim 12, and means extending between an axially spaced pair of said rods for maintaining the axial spacing of the convolutions of said other coil portion.

14. A support for an induction heating coil unit including an induction heating coil having axially spaced convolutions and an inner surface, said support including underlying support means upon which a portion of said coil is disposed and overhead support means for vertically supporting another portion of said coil in suspension, said overhead support means including support rails, means supporting said support rails in overlying relationship with respect to said other coil portion, and interconnecting means between said support. rails and said other coil portions including guide rails extending longitudinally of the coil axis and engaging the inner surface of said other coil portions and means extending between the coil convolutions of said other coil portion and having opposite ends interconnected one with said support rails and the other with said guide rails, the interconnection of at least one of said opposite ends with the corresponding support rail and guide rail being adjustable to vary the distance between the corresponding support rail and guide rail.

15. The support according to claim 14, wherein said support rails are axially spaced apart with respect to said coils and said means extending between said coil convolutions includes a plurality of rods associated with each support rail and having upper ends interconnected with the corresponding support rail and lower ends interconnected with a different one of said guide rails.

16. The support according to claim 14, wherein said support rails are transversely spaced apart with respect to the coil axis and each of said guide rails is disposed vertically beneath one of said support rails, and wherein said means extending between said coil convolutions includes a plurality of rods associated with each of said support rails and having upper ends interconnected with the corresponding support rail and lower ends interconnected with the guide rail therebeneath. 

1. A support for an induction heating coil unit including an induction heating coil having axially spaced convolutions enclosed by insulating means having an inner surface spaced radially inwardly of said convolutions, said support including underlying support means on which a portion of said coil unit is disposed and overhead support means for vertically supporting another portion of said coil unit in suspension, said overhead support means including support rails, means supporting said support rails in overlying relationship with respect to said other coil unit portion, and interconnecting means between said support rails and said other coil unit portion including metal guide rails extending longitudinally of the coil axis and engaging the inner surface of the insulating means of said other coil unit portion, and rod means extending through said insulating means and between coil convolutions and having opposite ends connected one to said support rails and the other to said guide rails.
 2. The support according to claim 1, wherein said support rails are axially spaced apart with respect to said coil, and said rod means includes a plurality of rods associated with each support rail and having upper ends interconnected with the corresponding support rail and lower ends interconnected each with a different one of said guide rails.
 3. The support according to claim 2, wherein the interconnection of at least one of the ends of at least one of said rods with the corresponding support rail and guide rail is adjustable to vary the distance between the corresponding support rail and guide rail.
 4. The support according to claim 2, wherein said coil has input and discharge ends, and means outwardly adjacent said discharge end and operable to engage a workpiece in said coil to guide movement of said workpiece in the direction from said input toward said discharge end.
 5. The support according to claim 1, wherein said support rails are transversely spaced apart with respect to the coil axis and each of said guide rails is disposed vertically beneath one of said support rails, and wherein said rod means includes a plurality of rods associated with each of said support rails and having upper ends interconnected with the corresponding support rail and lower ends interconnected with the guide rail therebeneath.
 6. The support according to claim 5, wherein the interconnection of at least one of the ends of at least one of said rods with the corresponding support rail and the guide rail therebeneath is adjustable to vary the distance between the support rail and guide rail.
 7. The support according to claim 1, wherein said coil has input and discharge ends, and means outwardly adjacent said discharge end and operable to engage a workpiece in said coil to guide movement of said workpiece in the direction from said input toward said discharge end.
 8. A support for an induction heating coil unit including an induction heating coil having axially spaced convolutions and an inner surface, said support including underlying support means on which a portion of said coil is disposed and overhead support means for vertically supporting another portion of said coil in suspension, said overhead support means including support rails, means supporting said support rails in overlying relationship with respect to said other coil portion, interconnecting means between said support rails and said other coil portion including means extending between the coil convolutions of said other coil portion and guide rails extending longitudinally of the coil axis and engaging the inner surface of said other coil portion, and cooling fluid conduit means extending longitudinally of said rails.
 9. A support for an induction heating coil unit including an induction heating coil having axially spaced convolutions and an inner surface, said support including underlying support means on which a portion of said coil is disposed and overhead support means for vertically supporting another portion of said coil in suspension, said overhead support means including support rails, means supporting said support rails in overlying relationship with respect to said other coil portion, interconnecting means between said support rails and said other coil portion including means extending between the coil convolutions of said other coil portion and guide rails extending longitudinally of the coil axis and engaging the inner surface of said other coil portion, said support rails extending generally transverse to the coil axis.
 10. A support for an induction heating coil unit including an induction heating coil having axially spaced convolutions and an inner surface, said support including underlying support means on which a portion of said coil is disposed and overhead support means for vertically supporting another portion of said coil in suspension, said overhead support means including support rails, means supporting said support rails in overlying relationship with respect to said other coil portion, and interconnecting means between said support rails and said other coil portion including means extending between the coil convolutions of said other coil portion and guide rails extending longitudinally of the coil axis and engaging the inner surface of said other coil portion, said support rails being axially spaced apart with respect to said coil, said interconnecting means including a plurality of rods associated with each support rail and having upper ends interconnected with the corresponding support rail and lower ends interconnected with a different one of said guide rails, said interconnection of at least one of the ends of at least one of said rods with the corresponding support rail and guide rail being adjustable to vary the distance between the corresponding support rail and guide rail, and cooling fluid conduit means extending along each of said guide rails.
 11. The support according to claim 10, and means extending between an axially spaced pair of said rods for maintaining the axial spacing of the convolutions of said other coil portion.
 12. A support for an induction heating coil unit including an induction heating coil having axially spaced convolutions and an inner surface, said support including underlying support means on which a portion of said coil is disposed and overhead support means for vertically supporting another portion of said coil in suspension, said overhead support means including support rails, means supporting said support rails in overlying relationship with respect to said other coil portion, and interconnecting means between said support rails and said other coil portion including means extending between the coil convolutions of said other coil portion and guide rails extending longitudinally of the coil axis and engaging the inner surface of said other coil portion, said support rails extending generally parallel to the coil axis and being transversely spaced apart with respect to the coil axis, each of said guide rails being disposed vertically beneath one of said support rails, said interconnecting means including a plurality of rods associated with each of said support rails and having upper ends interconnected with the corresponDing rails and lower ends interconnected with the guide rail therebeneath, the interconnection of at least one of the ends of at least one of said rods with the corresponding support rail and the guide rail therebeneath being adjustable to vary the distance between the support rail and guide rail, and cooling fluid conduit means extending along each of said guide rails.
 13. The support according to claim 12, and means extending between an axially spaced pair of said rods for maintaining the axial spacing of the convolutions of said other coil portion.
 14. A support for an induction heating coil unit including an induction heating coil having axially spaced convolutions and an inner surface, said support including underlying support means upon which a portion of said coil is disposed and overhead support means for vertically supporting another portion of said coil in suspension, said overhead support means including support rails, means supporting said support rails in overlying relationship with respect to said other coil portion, and interconnecting means between said support rails and said other coil portions including guide rails extending longitudinally of the coil axis and engaging the inner surface of said other coil portions and means extending between the coil convolutions of said other coil portion and having opposite ends interconnected one with said support rails and the other with said guide rails, the interconnection of at least one of said opposite ends with the corresponding support rail and guide rail being adjustable to vary the distance between the corresponding support rail and guide rail.
 15. The support according to claim 14, wherein said support rails are axially spaced apart with respect to said coils and said means extending between said coil convolutions includes a plurality of rods associated with each support rail and having upper ends interconnected with the corresponding support rail and lower ends interconnected with a different one of said guide rails.
 16. The support according to claim 14, wherein said support rails are transversely spaced apart with respect to the coil axis and each of said guide rails is disposed vertically beneath one of said support rails, and wherein said means extending between said coil convolutions includes a plurality of rods associated with each of said support rails and having upper ends interconnected with the corresponding support rail and lower ends interconnected with the guide rail therebeneath. 